Process in the manufacture of flexible containers



E- W. PLATT Oct. 18, 1966 PROCESS IN THE MANUFACTURE OF FLEXIBLECONTAINERS Filed July 1, 1964 FIG. 2

United States Patent PROCESS IN THE MANUFACTURE OF FLEXIBLE CONTAINERSEric W. Plait, 14 Harcourt St., New Farm, Brisbane, Queensland,Australia Fiied July 1, 1964, Ser. No. 379,616 (Ilaims priority,appiication Australia, July 8, 1963, 32,776/63 3 (Claims. (Ci. 93-35)This invention relates to an improved flexible container and the processin its manufacture, and is particularly directed to a rapid andefflcient method of separately sealing, unsealing, and rescaling themouth opening of each of a number of separate bag units which go to makeup the flexible container.

The paper bag has been in use for many years as a means for packaginggoods for carrying purposes. Following the recent development of plasticmaterial there have been occasions when it has been found preferable toreplace a paper bag with one constructed from a thin sheet of polyvinylchloride or some other suitable plastic substance. The use of a plasticbag introduces the acceptable properties of added strength andtransparency, and has the definite advantage over a paper bag in that itmay be used for the carriage of liquid, a use to which a paper bagcannot be satisfactorily applied.

In the known construction of paper bags, and in the more recentconstruction of plastic bags, no provision appears to have been made fora rapid sealing of the bag opening to retain the goods therein; a rapidunsealing of the bag opening to remove some of the goods therefrom; anda rapid rescaling of the bag opening after some of the goods have beenremoved therefrom to retain the remaining goods in closed conditionwithin the bag.

It is the principal object of the present invention to meet the aboveweakness revealed in present day flexible bag construction.

Other objects of the invention will become apparent as the descriptionproceeds.

In accordance with the present invention I provide a method for theconstruction of flexible containers, said method consisting of theprocess of selecting a rectangular sheet of flexible materialconsiderably greater in length than in width; folding the sheet about alongitudinal axis to enable the two side edges to lie in proximity toone another; applying one or more narrow strips of adhesive substanceover the surface of the folded sheet, each strip extending for the fulllength of the flexible material; sealing the end edges of the foldedsheet to form a long flexible container; applying a number ofintermediate seals to divide said flexible container into a number ofindividual bag units each having a mouth opening which may be sealed andresealed by the application of finger pressure to the adhesivesubstance.

One specific method of application of this invention consists in theprocess of selecting a rectangular sheet of fluid impermeable flexiblematerial having predetermined length and width; folding said sheet aboutits mid-axial line such that its two side edges meet; inwardly foldingeach of the meeting side edges to form a pair of inturned lips of equalwidth along the mouth edge of the container; applying a fluidimpermeable seal along the open end edges of the container formed fromfolding the sheet of flexible material; applying a fluid impermeableseal at spaced intervals across the width of the folded container todivide it into a number of individual bag units; forming a fluidimpermeable adhesion between the confronting surfaces of the inturnedlips, said adhesion being limited to the extent of providing a narrowopening to receive a length of tubing for the admission or withdrawal offluid or granular substance into or from each individual unit;

3,279,331 Patented Oct. 18, 1966 resealing the opening after the fluidor granular substance has been admitted or withdrawn from an individualunit of the container; and forming perforations extending within thelength of each seal dividing the container into a number of individualunits to separate each bag unit from the container as desired.

In applying this invention to paper bag construction, the seals at theend edges of the container, and the intermediate seals dividing thecontainer into a number of individual bag units, are formed by the useof any well known strongly binding glutinous material.

When applying this invention to the construction of a flexible plasticcontainer it has been found preferable to form the rectangular sheetfrom polyvinyl chloride. As this is a thermoplastic substance, the sealsat the end edges of the container and the intermediate seals dividingthe container into a number of individual bag units may be formed by theapplication of heat or high frequency current to the outer surface ofthe folded sheet.

When applying the intermediate seals to divide the flexible containerinto a number of individual bag units, it is preferable to form a tearstrip down the centre of each of the intermediate seals. This tear strippermits easy detachment of bag units from the container length, and maybe constructed of any well known form, such as a strip of weakenedmaterial, or a line of perforations.

It has been found convenient to support the container length by windingit around the outer surface of a roller housed within a dispenser. Whenit is desired to sever a bag unit from the container it is onlynecessary to unwrap the required length of container from the roller tothe extent of bringing its tear strip into contact with a sharp edgelocated along one side of the dispenser.

Although for general purposes the seal dividing the container intoseparte bag units is formed as a straight sealing strip, for novelty andadvertising purposes, the side edges of the dividing seals may be curvedto present a series of bag units shaped into the form of animals,clowns, or other novelties particularly appropriate as a method ofdrawing public attention to the virtues of the substance within thebags.

The narrow strip or strips of adhesive substance over the surface of thefolded sheet may be applied thereto in a number of different ways. Onemethod is to have a surface layer of suitable adhesive material directlysprayed onto the sheet. A second method is to utilize a double sidedadhesive tape, one side adhering firmly to the surface of the foldedsheet and the other side providing the desired sealing and rescalingfacilities across an opening in the container. A third method is toutilize a single sided adhesive tape. One section of the width of thissingle sided adhesive tape adheres to the surface of the sheet adjacentthe edge of an opening into the container, whilst the other section ofthe tape width forms a tongue which extends slightly into the openingand thereby serves as a strip for sealing and resealing the opening. Afourth method is to fold the width of a long double sided adhesive stripover the end edge of an inner wall of the contaner. In this lattermethod a sealing strip is provided which is double acting in that itserves to seal and reseal openings on either side of the wall.

-On each occasion when a double sided adhesive tape is employed it maybe expedient to supplement the grip of the tape over the surface of thefolded sheet by the addition of a slightly stronger adhesive substanceat spaced intervals along its length. This would expel any chance of thetape being pulled away from the surface of the container when applied asa seal across openings within the container.

When forming the container it has been found convenient under certaincircumstances to extend the end edges of the container walls slightlybeyond the outer side edges of the strips of adhesive substance. Thisenables tabs to be formed which serve to provide finger gripping meansat positions in proximity to the scalable opening. To break the sealformed by the adhesive substance across the opening, an outward pull isapplied manually to these tabs.

It has been found in practice that a container having a sealing stripapplied thereto in the manner as revealed in this specification can berapidly and tightly sealed and resealed at least thirty times withoutlosing any power of adhesion from the adhesive material.

The container, together with each of the bag units formed from thiscontainer, may be constructed of a particular cross-sectional shapedepending upon the use to which it is to be applied. A number ofsuitable shapes will now be described by reference to FIGURES 1 to 14 ofthe accompanying drawing.

Referring to FIG. 1, the initial fold of the rectangular sheet is formedabout a mid-axial line, and the mouth of the container is providedbetween a pair of inturned lips 1, 2. A pair of matching double sidedadhesive tapes 3, 4, pass over the two facing surfaces of the inturnedlips. In this type of construction, by the use of fluid impermeablepolyvinyl chloride sheeting as the substance forming the container, themouth opening may be sealed to retain liquid therein, and may beunsealed to the extent of providing a narrow opening to receive a lengthof tubing for the passage of liquid to or from the container. A liquidcontainer of this form has the advantage that owing to its flexibility,the weight of the liquid may retain the container in upright dispositionwhen placed upon a fiat surface. In addition, the pressure of any liquidor granular substance passing into the pockets 5, 6, formed by theinturned lips will assist to retain the seal over the mouth opening ofthe container. The use of a pipe or a straw as a tubular length to passthe liquid into the container and withdraw the liquid from the containerserves to prevent the retention of liquid over the adhesive surfaces,which under some circumstances may result in a deterioration of theholding power of the adhesive surfaces.

In FIG. 2 a single inturned lip 7 is formed adjacent the mouth openingof the container formed by the flexible sheet. The end edge of thestraight side 3 of the container extends slightly beyond the mouthopening to form a tab which enables an easy grip to be obtained toassist in unsealing the container mouth. The adhesive material forclosure of the mouth opening consists of a strip of single sidedadhesive tape with the width section 9 having its adhesive surfacefirmly attached to the inner surface of the inturned lip 7, and thewidth section depending below the lower edge of the inturned lip 7 toenable the closure of the mouth opening when the adhesive surface overthe section 10 engages the inner surface of the side wall 8 of thecontainer. This construction has the advantage that very little of theadhesive surface contacts the material as it is withdrawn from thecontainer. It may be desired to package a granular substance within thisform of container construction and withdraw it without any contact withan adhesive layer. This may be effected by forming a vertical slitthrough the tape widths 9, 10, and extending this slit through the wallof the inturned lip 7. This construction permits a discharge of thematerial from the container through the slit in the inturned lip whenthe mouth of the opening is unsealed, and a drawing together of thesides of the slit when the adhesive surface 10 seals the mouth opening.

In FIG. 3 the construction is very similar to that of FIG. 2 with theexception that the straight side of the container is lengthened slightlyto form a scalable lid which has a downward fold 11. The end of thisdownward fold is formed with an inturned lip 13 to permit the housing ofthe lower portion of a double sided adhesive tape 12. The inwardlyfacing surface at the upper section of the tape 12 permits the end ofthe lid to be scaled against the outer Wall face of the container, andthe inturned lip 13 provides means for gripping the lid when it isdesired to break the seal. The additional compartment formed by the lidmay serve as a storage for any implements or materials desired tosupplement the main body of material within the container.

In FIG. 4 the seal of the mouth of the container is effected by a stripof double sided adhesive tape 15 having one side attached to the innersurface face of the container and extending adjacent the edge of acontainer wall which assists in the formation of the mouth opening. Theother side wall of the container is extended beyond the mouth openinginto a downward fold 16 to serve as a lid for the container which has aninturned end to reoeive a further strip of double sided adhesive tape ina manner identical to that described with reference to FIG. 3.

The form of folds illustrated in FIGS. 5 and 6 again consists of acontainer having one side wall upwardly extending to assist in theformation of a mouth opening, and the other side wall extending beyondthe mouth opening into downward folds 18, 19, to serve as containerlids. In the embodiment of the invention as illustrated in FIG. 5, adouble sided adhesive tape 20 is bent over the upper end edge of theupright container wall 20a. This tape is finmly attached to 'both sidesof wall 20a. On account of the bend in this adhesive tape it may servethe dual purpose of sealing the :mouth opening by bringing the oppositewalls of the container into adhesive engagement with each other and alsoserves as a means for sealing the downward fold 18 of the lid of thecontainer to the outer surface of the container wall 20a. In FIG. 6 theupright wall 22a is provided with an inturned lip 22 over which thedouble sided adhesive tape 21 is attached to form the dual purpose seal.

The form of fol-d illustrated in FIG. 7 is particularly acceptable incases where it is desired to include a seala-ble pocket above thecontainer to house material suitable for use in association with thematerial within the container closure. If the container enclosureincludes a soft drink, the pocket may contain a drinking straw, or itmay contain flavoring essence to mix with the liquid within thecontainer to form a cocktail mixture. The scalable pocket may provide ahousing for advertising matter serving to advance the sale properties ofthe product included within the container. The pocket 23 may house adrinking straw 24 and the Wall 25 of the container serves to divide itsmouth portion from the pocket 23. The wall 26 of the container isextended beyond the mouth opening to form a lid with a downward foldportion 27. The sealing of the container mouth opening and the sealingof the pocket 23 is effected by the dual functioning of a strip ofdouble sided adhesive tape 28 bent to pass around the upper edge of thecontainer wall 25. A further strip 29 of double sided adhesive tape 29is attached to the inner surface of the downward fold portion 27 of thelid.

In FIG. 8 there is illustrated the application of the invention to acontainer formed as a single fold. In this form of fold the side walls30, 31 of the container extend slightly beyond the mouth opening toprovide adequate facilities for manually gripping the container when itis desired to unseal the mouth opening after it has been sealed. Thesealing strip 32 is a double sided adhesive tape attached to the innersurface of the container wall 3-1 adjacent the mouth opening. This formof container construction may well be adapted to paper containers andbag units as well as containers and bag units formed of plasticsheeting.

In FIG. 9 the fold is very similar to that of FIG. 8 with the exceptionthat the lower wall of the container is formed with a depending lip 34,and a double sided adhesive strip 35 is attached to the outer face ofthis lip to seal the mouth of the container against the opposing wallunder finger pressure applied to the outer surface of the container.This fold has an advantage over that illustrated in FIG. 8 in that thegrip of the seal across the mouth of the container may be supplementedby the pressure of some of the goods within the container.

In FIG. 10 there is illustrated a form of container which is initiallyclosed by heat sealing the two surfaces 36, 37 together. A pocket 49 isformed over the upper surface of the container. This form of containermay well be utilized as a carrier for fruit drinks, and a straw with apointed end may be housed within the pocket opening which is sealed by adouble sided adhesive strip 38 which brings the two inner side wallsurfaces of the pocket into sealed engagement with each other. When itis desired to withdraw drink from the container, the pocket opening isunsealed, and a hole is punctured through the floor of the pocket withthe pointed end of the straw. The straw is used to suck a desired amountof the drink from the container which is closed by resealing the pocketopening.

In FIG. 11, a folded container construction similar to that illustrated11 FIG. 9 is provided with the exception that the double sided adhesivetape 41 is provided over the inner surface of the wall 42 of thecontainer.

FIG. 12 is a modification of the fold construction illustrated in FIG. 7in that a single sided adhesive tape 4-3 is provided depending from theinside surface of one of the side walls of the container to seal themouth opening; a pocket 45 is provided to house matter which may berelevant to that supported within the container, and a double sidedadhesive strip 44 is provided to seal the end of a lid formed by thefolded extension 46 to the other side wall of the container. To obtainaccess into the container the lid is opened by manually breaking itsseal, and the seal at the mouth of the container is then likewisebroken. On removal of a desired quantity of material from the containerit is resealed at the mouth opening and the lid portion is againrescaled adjacent its end.

FIGS. 13 and 14 illustrate means for adapting this invention to aplastic container or a bag unit formed from this container for thepurpose of displaying an attractive variety of goods to their bestadvantage. In this construction the mouth opening is formed over therear surface of the container or bag which would be generally hid-denfrom the sight of the general public when on display.

In FIG. 13 the mouth opening is sealed by an upturned lip 48 having anouter surface which engages the outer face of a double side-d adhesivetape 49 fixed to the inner surface of the container wall 50. When it isdesired that articles be removed from the bag or container the seal ismanually broken, and the bag or container is resealed by fingerpressure.

FIG. 14 varies the construction of FIG. 13 in that the upturned lip isdispensed with. A double sided adhesive tape 51 is formed over the outersurface wall 52 of the container.

Whilst no reference has been made in the specification to adhesive tapesof any specific colour, it is to be understood that tapes in variouscolours are available and a most suitable colour for use with theadhesive materials would be dependent upon the particular class of goodsto be merchandised. i

A method of construction in accordance with this invention has extensiveadvantages over containers employed at the present time in the packagingof small goods or relatively small quantities of liquid. These areexemplified by the speed in which a bag may be sealed, and the fact thatsome of the goods may be removed from the bag while the remaining goodsare retained within the bag which may be sealed some thirty or moretimes with out any noticeable reduction in the holding power of theseal.

Whilst various embodiments of this invention have been disclosed in theforegoing description I desire that it be fully understood that thelimitation to the scope of this 6 invention is determined solely by theextent of the limitation imposed by the following claims: twisting,turning What I claim is:

1. A method of constructing flexible containers, said method comprisingthe steps of providing a sheet of flexible plastic material havingopposite surfaces and spaced longitudinal edges, said sheet beingconsiderably greater in width than in length; applying an elongatedstrip of single-sided adhesive tape into adhering engagement with onesurface of said flexible sheet close to one of said edges thereof, such,that a portion of the width of said tape extends beyond said edgethereof in form of a tongue having an exposed surface-coating ofadhesive material which latter faces in direction of the other surfaceof said sheet; folding said sheet of flexible material about at leastone folding line intermediate and parallel to said edges so as to format least two superposed panels having opposite inwardly directedportions of said one sur face and so that said edges lie in proximity toone another; inwardly folding that edge portion of the sheet which sup.-ports said single-sided adhesive tape to form an inturned lip; sealingthe respective end edges of the folded sheet to form a long flexiblecontainer; and applying at least one intermediate seal across the widthof said container to divide the same into individual smaller containersconstituting bag units each of which has a mouth opening which may besealed and rescaled by the application of pressure in a sense movingsaid exposed surface coating into contact with said one surface of theadjacent other panel which latter forms a portion of the outer wall ofthe respective individual container.

2. A method for the composition of flexible containers, said methodcomprising the steps of obtaining a sheet of flexible thermoplasticmaterial which is considerably greater in length than in width; applyingan elongated strip of single sided adhesive tape into adheringengagement with one surface of said flexible thermoplastic sheet closeto one side edge thereof such that portion of the width of said tapeextends beyond the associate side edge of the thermoplastic sheet in theform of a projecting tongue containing an exposed surface coating ofadhesive material; folding said sheet of flexible thermoplastic materialabout its longitudinal mid axis so that its two side edges lie inproximity to one another; inwardly folding the section of thethermoplastic material supporting said single sided adhesive tape toform an inturned lip; heat sealing the end edges of the folded sheet toform a long flexible container; and applying at least one intermediateheat seal across the width of said folded sheet to divide the containerinto individual smaller containers constituting bag units each of whichhas a mouth opening which may be sealed and rescaled by the applicationof finger pressure to move said exposed surface coating of adhesivematerial into contact with the inner surface of the adjacent flexiblematerial forming portion of the outer Wall of each individual container.

3. A method for the construction of flexible containers, said methodcomprising the steps of obtaining a sheet of flexible thermoplasticmaterial which is considerably greater in length than in width; applyingan elongated strip of single sided adhesive tape into adhering engagement with one surface of said flexible thermoplastic sheet adjacent oneside edge thereof such that portion of the width of said tape extendsbeyond the associated side edge of the thermoplastic sheet in the formof a projecting tongue containing an exposed surface coating of adhesivematerial; additionally applying an elongated stripof double sidedadhesive tape int-o flexible thermoplastic sheet to lie in a directionparallel to said single sided adhesive strip at a spaced distancetherefrom; folding said sheet of flexible thermoplastic material aboutits longitudinal mid-axis so that its two side edges lie in proximity toone another; inwardly folding the section of the thermoplastic materialwhich supports the single sided adhesive tape adjacent one side edge toform an inturned lip; applying a small concertina fold over the lengthof the flexible sheeting adjacent the edge supporting the single sidedadhesive tape to .provide a pocket for housing appropriate articlesoutside the confines of the container; heat sealing the end edges of thefolded sheet to form a long flexible container; and applying at leastone intermediate heat seal across the width of said folded sheet todivide the container into individual smaller containers constituting bagunits each of which has a mouth opening which may be sealed and resealedby the application of finger pressure to move said exposed surfacecoating of adhesive material on the projecting tongue into contact Withthe inner surface of the adjacent flexible material forming portion ofthe outer Wall of each individual container; bending a section of thewall of the folded sheet which extends beyond the container to fonrn alid which covers the mouth opening and the pocket of each individualcontainer; and detachably sealing the said lid to the outer Wall bringthe end section of its inner surface into engagernent with the outeradhesive surface formed over the strip of double sided adhesive tape.

References Cited by the Examiner UNITED STATES PATENTS 2,116,571 5/1938Gurwick 93-35 2,265,075 12/ 1941 Knuetter 93-35 2,401,109 5/ 1946R-oh-din 93-35 2,793,743 5/ 1957 Lefeovre 22962 X 2,949,370 8/ 1960Hughes.

2,991,001 7/ 1961 Hughes 229-62 3,045,891 7/ 1962 Alvarez .93353,079,066 2/1963 -Ro0p 229-6 3,143,278 8/1964 Hieb'ert 22 BERNARDSTICKNEY, Primary Examiner.

FRANKLIN T. GARRETT, Examiner.

surface of said container by applying finger pressure to 20 D. M.BOCKENEK, Assistant Examiner

1. A METHOD OF CONSTRUCTING FLEXIBLE CONTAINERS, SAID METHOD COMPRISING THE STEPS OF PROVIDING A SHEET OF FLEXIBLE PLASTIC MATERIAL HAVING OPPOSITE SURFACES AND SPACED LONGITUDINAL EDGES, SAID SHEET BEING CONSIDERABLY GREATER IN WIDTH THAN IN LENGTH; APPLYING AN ELONGATED STRIP OF SINGLE-SIDED ADHESIVE TAPE INTO ADHERING ENGAGEMENT WITH ONE SURFACE OF SAID FLEXIBLE SHEET CLOSE TO ONE OF SAID EDGES THEREOF, SUCH, THAT A PORTION OF THE WIDTH OF SAID TAPE EXTENDS BEYOND SAID EDGE THEREOF IN FORM OF A TONGUE HAVING AN EXPOSED SURFACE-COATING OF ADHESIVE MATERIAL WHICH LATTER FACES IN DIRECTION OF THE OTHER SURFACE OF SAID SHEET; FOLDING SAID SHEET OF FLEXIBLE MATERIAL ABOUT AT LEAST ONE FOLDING LINE INTERMEDIATE AND PARALLEL TO SAID EDGES SO AS TO FORM AT LEAST TWO SUPERPOSED PANELS HAVING OPPOSITE INWARDLY DIRECTED PORTIONS OF SAID ONE SURFACE AND TO THAT SAID EDGES LIE IN PROXIMITY TO ONE ANOTHER; INWARDLY FOLDING THAT EDGE PORTION OF THE SHEET WHICH SUPPORTS SAID SINGLE-SIDED ADHESIVE TAPE TO FORM AN INTURNED LIP; SEALING THE RESPECTIVE END EDGES OF THE FOLDED SHEET TO FORM A LONG FLEXIBLE CONTAINER; AND APPLYING AT LEAST ONE INTERMEDIATE SEAL ACROSS THE WIDTH OF SAID CONTAINER TO DIVIDE THE SAME INTO INDIVIDUAL SMALLER CONTAINERS CONSTITUTING BAG UNITS EACH OF WHICH HAS A MOUTH OPENING WHICH MAY BE SEALED AND RESEALED BY THE APPLICATION OF PRSSURE IN A SENSE MOVING SAID EXPOSED SURFACE COATING INTO CONTACT WITH SAID ONE SURFACE OF THE ADJACENT OTHER PANEL WHICH LATTER FORMS A PORTION OF THE OUTER WALL OF THE RESPECTIVE INDIVIDUAL CONTAINER. 